Advertisements
Advertisements
प्रश्न
What is a pulley?
Advertisements
उत्तर
It is a flat circular disc with a groove in its edge and a rope passing through the groove. It is capable of rotating around a fixed point passing through its central axis called axle.
APPEARS IN
संबंधित प्रश्न
State whether the following statement is True or False.
A pulley changes the direction of force.
Explain how a gear system can be used to obtain Change in direction of rotation. Given one example.
What should be the gear ration of a car : equal to 1, less than 1 or greater than 1, while ascending a hill ?
What is a single movable pulley? What is its mechanical advantage in the ideal case?
Give reason for the following:
The lower block of a block and tackle pulley system must be of negligible weight
(a) Fig represents an incomplete diagram of a simple string pulley system. Copy this diagram on a new page and complete it and mark where the effort must be applied to lift the load.
(b) What is the velocity ratio of this system?
(c) If the pulley system is 80% efficient and the load is 720 N, then
(i) What effort must be applied to lift the load?
(ii) What work must be done must be done in lifting the load through a distance of 2 m using this machine?
A type of single pulley is very often used as a machine even though it does not give any gain in mechanical advantage. For what purpose is such a pulley used?
What is the relation between the mechanical advantage and the number of strands of string used to support the load, in a ‘block and tackle’ set-up?
What is a block and tackle system of pulleys? What precautions would you observe while rounding the string so that the effort is applied in the downward direction?
Name the type of single pulley that has an ideal mechanical advantage equal to 2. Draw a labelled diagram of the pulley mentioned by you.
